Sleeve part (4)
I believe the answer is:
cuff
'sleeve part' is the definition.
('cuff' is part of 'sleeve')
This is the entire clue.
(Other definitions for cuff that I've seen before include "Smack; end of shirt sleeve" , "Blow; end of sleeve" , "Blow - on the wrist?" , "Smack; Moonstone sergeant" , "minor assault" .)